Israel has condemned a decision by Iran's navy to sail two of its ships through the Suez Canal to the Mediterranean Sea.

Foreign Minister Avigdor Lieberman said the world should act against Iran's "recurring provocations".

The vessels were planning to sail to Syria, Mr Lieberman said.

There has been no response from Tehran, but reports last month said Iran's navy planned to send a "fleet" to the Mediterranean Sea for a year.

"During the mission, the fleet of warships will enter the waters of the Red Sea and then will be dispatched to the Mediterranean Sea," Lieutenant Commander Rear Admiral Gholam Reza Khadem-Bigham was quoted as saying in January by the semi-official Fars news agency.

He said the fleet would gain "good intelligence and information of the regions it is due to visit".

A report in Israel's Yedioth Ahronot newspaper said the Iranian vessels were a Mk-5 frigate and a supply vessel.

Iran's Mk-5 frigates date from the 1960s and were sold by the UK.

But Rear Admiral Khadem-Bigham said in January the vessels would include a "home-made" destroyer, likely to be a reference to vessels the country starting producing itself last year, based on the British design.

The first vessel, the Jamaran, was unveiled a year ago.

'Recurring provocations'

Mr Lieberman's attack on the plan came as he addressed US Jewish leaders in Jerusalem.

"Tonight, two Iranian warships are meant to pass through the Suez Canal to the Mediterranean Sea and reach Syria, something that has not happened in many years," he said.

"To my regret, the international community is not showing readiness to deal with the recurring Iranian provocations. The international community must understand that Israel cannot forever ignore these provocations."

Mr Lieberman said Iran's navy had not sailed past Israel's coast for years.

The Suez Canal Authority said no Iranian warships had used the canal since 1979 but pointed out that all ships were free to do so as long as they did not come from a country at war with Egypt.

Tensions between Israel and Iran have continued to grow amid Tehran's ongoing nuclear programme, which Iran insists is for peaceful purposes only.

It is believed to be the first time since Iran's 1979 Islamic Revolution that Iranian warships have passed through the waterway.

The Iranian vessels entered the canal at 0545 local time (0345 GMT) and passed into the Mediterranean at 1530 (1330 GMT)," the source at the canal authority told Reuters.

"Their return is expected to be on 3 March," the source added.

Diplomatic significance

Iran's request stated the vessels would have no military equipment, nuclear materials or chemicals on board, the Egyptian defence ministry is quoted as saying.

A Suez Canal official said earlier Egypt could only have denied transit through the strategic waterway in case of war.

But the significance of the deployment is entirely diplomatic, says the BBC's diplomatic correspondent Jonathan Marcus.

He says the two Iranian vessels do not represent any significant threat to either the Israeli navy or US vessels in the Mediterranean.

The ships involved are the Alvand - thought to be a British-built Vosper Mark 5 class frigate - and a supply vessel, the Kharg, also British-built.

The Alvand, a missile-carrying frigate, was launched in 1968. It is an impressive vessel by the standards of the Iranian navy, but no match for comparable Western warships nor the sophisticated missile boats of the Israeli navy, our correspondent says.

What is clear is that this deployment is not a direct response to the current upheavals in the Middle East, he adds.

Iran's semi-official Fars news agency reported in January that Iranian navy cadets were going on a year-long training mission through Suez and into the Mediterranean - well before the protests that have swept the leaders of Tunisia and Egypt from power.

But coming in the wake of these political changes the Iranian deployment will be seen by the Israeli in particular as even more destabilising, our correspondent says.

Israel considers Iran a threat because of its controversial nuclear programme, development of ballistic missiles, support for Lebanese and Palestinian militant groups, and Tehran's repeated anti-Israel rhetoric.

Last week, Israeli Foreign Minister Avigdor Lieberman said: "To my regret, the international community is not showing readiness to deal with the recurring Iranian provocations.

"The international community must understand that Israel cannot forever ignore these provocations."

An Iranian military commander has said Iran would take pre-emptive action against its enemies if it felt its national interests were endangered.

Mohammad Hejazi, deputy head of Iran's armed forces, made his comments to the Iranian Fars news agency.

Iran is facing mounting international pressure over its controversial nuclear programme.

On Monday it unveiled fresh military exercises in the south that it said was to protect its nuclear sites.

"Our strategy now is that if we feel our enemies want to endanger Iran's national interests, and want to decide to do that, we will act without waiting for their actions," Mr Hejazi told Fars.

The BBC's Iran correspondent James Reynolds says Iran's military and political leaders routinely stress that they are capable of defeating the country's enemies should the need arise.

Their comments are closely scrutinised by those trying to work out Iran's military capability and also its overall intentions, he adds.

Iran insists its uranium enrichment programme is for peaceful purposes but Western powers suspect Tehran intends to make weapons.

Neither Israel nor the US have ruled out military action if sanctions and diplomacy fail to rein in Iran's nuclear activities.

In recent weeks speculation has been increasing that Israel may launch a military strike on Iran's nuclear facilities.

Last week, US Defense Intelligence Agency director Lt Gen Ronald Burgess told the US Congress that Iran may launch missiles if it is attacked but was unlikely to initiate or intentionally provoke a conflict.

On Monday senior inspectors from the UN's International Atomic Energy Agency (IAEA) began another round of talks in Tehran - their second in three weeks.

They say they want Iranian reassurances about "possible military dimensions" to the nuclear programme.

Late last year Iran conducted 10 days of military exercises near the Strait of Hormuz at the entrance to the Gulf.

Iran has threatened to block the strait, through which 20% of the world's oil exports pass, in retaliation for Western sanctions over its nuclear plans.

Ray, if they block the strait they are leaving themselves wide open for a strong retaliation from the air. This problem isn't going away. Meanwhile, President Obama ignores it because he is more concerned about re-election in November than exercising his presidential duties.

Diane, I am a firm believer in the fact that this may not be the case. By ignoring this and the impact on Israel, Obama is costing himself votes and I would think that would not be what he wants. I believe that his dislike for Israel in relationship to his natural support for the Arab Nations is such that he is making the choice to ignore it as that loyalty is greater than the votes; he honestly thinks that he can make it without those votes. That is probably going to be his own undoing; the fact that his demonstrates such arrogant disdain for anything that does not fit into his personal agenda; his personal agenda being completely different from the one he should assume as the President of the U.S.

Jim shared on another thread Obama's own words when interviewed prior to his being elected President that spells out this very clearly. His priority has always been to his Muslim brotherhood.

Israeli PM Benjamin Netanyahu has said time is running out to put a stop to Iran's nuclear programme.

Speaking to a pro-Israel conference in the US, Mr Netanyahu said he could not allow his people to "live in the shadow of annihilation".

Israel fears Iran is seeking to develop nuclear weapons, and speculation of a pre-emptive strike has recently grown.

US President Barack Obama has said there is still time for diplomacy, but that all options remain open.

Tehran insists its nuclear plans are peaceful.

Speaking to some 13,000 delegates at the American-Israel Public Affairs Committee (Aipac) on Monday night, Mr Netanyahu reiterated that Israel was "determined to prevent Iran having nuclear weapons".

"Unfortunately, Iran's nuclear programme has continued to march forward," he said.

"Israel has waited for diplomacy to work, we've waited for sanctions to work. None of us can afford to wait much longer.

"As prime minister of Israel I will never let my people live in the shadow of annihilation."

He stressed that all options were on the table, but that containment - leaving Iran to develop its programme under monitoring - was "not an option".

"The Jewish state will not allow those who seek our destruction the means to achieve that goal. A nuclear armed Iran must be stopped," Mr Netanyahu told Aipac.

He waved a copy of a 1944 letter in which the US War Department refused Jewish leaders' requests to bomb the Auschwitz Nazi death camp on the grounds that it "might provoke even more vindictive action by the Germans".

"Today, we have a state of our own," he said. "And the purpose of the Jewish state is to defend Jewish lives and to secure the Jewish future."

'Diplomatic window'

In his meeting with Mr Netanyahu at the White House on Monday, Mr Obama said the bond between their countries was "unbreakable".

He said the US believed there was "still a window that allows for a diplomatic resolution", on Iran, but added that the US would consider "all options".

Both Israel and the US understand the "costs of any military action", he said.

Mr Netanyahu replied that Israel "must reserve the right to defend itself" and must remain "the master of its fate".

The two leaders are said to have a cool relationship. In May 2011, during a visit to Washington, correspondents noted the frosty body language between the two leaders.

In his own address to Aipac on Sunday, Mr Obama said there had been too much "loose talk" of war with Iran, which was benefiting Tehran as it was driving up the price of oil, which funds the nuclear programme.

He said Iran was isolated and there was an opportunity "for diplomacy - backed by pressure - to succeed".

"Iran's leaders should know that I do not have a policy of containment - I have a policy to prevent Iran from obtaining a nuclear weapon," he said.

"And as I've made clear time and again during the course of my presidency, I will not hesitate to use force when it is necessary to defend the United States and its interests."

After years of international pressure and the repeated failure of negotiations and offers of talks with Tehran, talk has grown in recent months of a pre-emptive strike against Iranian nuclear facilities.

The US has pushed for the imposition of ever-stricter sanctions against Iran, including recent curbs on its central bank and its ability to export oil to the West.

Yet despite the ratcheting up of sanctions, speculation has been mounting that Israel might choose to attack Iran sometime during 2012.

Hours before the US-Israeli meetings Yukiya Amano, head of the UN's nuclear agency, reiterated that his organisation had "serious concerns" that Iran could be hiding secret work on developing atomic weapons.

Citing a recent agency report, he said International Atomic Energy Agency (IAEA) was unable "to conclude that all nuclear material in Iran is in peaceful activities".

Analysis

Jonathan Marcus

BBC diplomatic correspondent

There were two speeches and two vital sets of messages, one directed squarely at Tehran - that both Israel and the United States will do everything they can to prevent Iran having a nuclear weapon.

But just as important were the messages between Israel and its main ally, with Prime Minister Benjamin Netanyahu insisting that Israel cannot give up its own freedom of action, while from President Barack Obama, there was the clearest assertion yet that Washington does not believe in containment. Iran will not get nuclear arms on this president's watch.

For Mr Obama there is still time for diplomacy and sanctions to take effect. But the fundamental problem remains: as Iran's nuclear facilities go underground, Israel's window of opportunity to act militarily runs out long before that of the Americans.

And that leaves one central question unanswered: is Israel ready to forego a strike against Iran trusting that the Americans will act at some point in the future?

Iran says it is prepared to give the UN's International Atomic Energy Agency (IAEA) access to a key military site.

IAEA inspectors wanted to visit Parchin last month to clarify the "possible military dimensions" of Iran's nuclear programme, but they were denied entry.

But on Tuesday, Iran's mission to the IAEA said it had asked the agency to "combine all related issues" and then "once more, access would be granted".

The West suspects Iran wants to build a nuclear bomb - an accusation it denies.

'Serious concerns'

The complex at Parchin, south of Tehran, is dedicated to the research, development and production of ammunition, rockets and explosives.

Concerns about its possible role in Iran's nuclear programme emerged in 2004, when reports surfaced that a large explosives containment vessel had been built there to conduct hydrodynamic experiments.

The IAEA has warned that hydrodynamic experiments, which involve high explosives in conjunction with nuclear material or nuclear material surrogates, are "strong indicators of possible weapon development".

In 2005, IAEA inspectors were twice given access to parts of Parchin and were able to take several environmental samples.

A report issued in 2006 noted that they "did not observe any unusual activities in the buildings visited, and the results of the analysis of environmental samples did not indicate the presence of nuclear material".

But suspicions about Parchin persisted and the IAEA has repeatedly sought to visit the facility again. The latest attempt came in February, when inspectors were turned away despite "intensive efforts".

The IAEA subsequently complained it had been unable to "provide credible assurance about the absence of undeclared nuclear material and activities in Iran" and that it continued to have "serious concerns regarding possible military dimensions to Iran's nuclear programme".

On Tuesday, Iran's mission in Vienna issued a statement suggesting that IAEA inspectors would once again be permitted to visit Parchin.

"Considering the fact that it is a military site, granting access is a time consuming process and cannot be permitted repeatedly," it said.

"In the light of this background and principle the Agency was requested to combine all related issues such as hydrodynamic experiments, and then once more, access would be granted."

Iran has made it clear that if it is attacked either by Israel or the United States it will respond in kind. But just what could Iran do to strike back? What would be the consequences, both in the region and inside Iran itself? Indeed, could the potential consequences of an Israeli strike be so serious as to make military action the least preferable option in terms of constraining Iran's nuclear programme?

Long-distance missiles

"Iran's ability to strike back directly against Israel is limited," says Mark Fitzpatrick, director of the Non-Proliferation and Disarmament Programme at the London-based International Institute for Strategic Studies (IIS.

"Its antiquated air force is totally outclassed by the Israelis and it has only a limited number of ballistic missiles that could reach Israel."

Iran's air force, which includes Mig-29s, is not seen as a match for its Israeli or US counterparts

Mr Fitzpatrick says Iran's missile arsenal includes "a modified version of the Shahab-3, the Ghadr-1, which has a range of 1,600km (995 miles), but Iran only has about six transporter-erector launchers for the missile". "Iran's new solid-fuelled missile, the Sajjil-2, can also reach Israel, but it is not yet fully operational," he adds. But, Mr Fitzpatrick argues that "both of these missiles are too inaccurate to have any effect against military targets when armed with conventional weapons". "Nor are they a very effective way to deliver chemical or biological weapons, and Iran does not have nuclear weapons." In summary, he believes that "an Iranian missile strike would be only a symbolic gesture".

Enlisting allies

Hezbollah is said to have thousands of rocket launchers in Lebanon

Mr Fitzpatrick believes Iran is more likely to respond against Israel "asymmetrically, and through proxies". Its ally, the Shia Islamist group Hezbollah, has more than 10,000 rocket launchers in southern Lebanon, many of them supplied by Iran.

"These are mostly 25km-range (16-mile) Katyushas, but also Fahr-3 (45km; 28 miles), Fajr-5 (75km; 47 miles), Zelzal-2 (200km; 124 miles) and potentially Fateh-110 (200km) plus about 10 Scud-D missiles that can pack a 750kg (1,653lb) payload and hit all of Israel." He says that the Palestinian Islamist movement Hamas, which controls the Gaza Strip, could also attack Israel with shorter-range rockets.

The great danger here is of a more extensive conflict breaking out either between Israel and Hezbollah, or Israel and Hamas. With so much instability in the Middle East - not least because of the Syria crisis - there is a very real risk of an Israeli strike sparking a much broader regional conflagration.

These could all be used to close off the vital oil artery - the Strait of Hormuz.The US Navy is confident that it could re-open the Strait. But this risks an extended naval conflict between the US and Iran, and in the short term, there could be a significant impact upon oil prices.

Covert action

Daniel Byman, a counter-terrorism expert at the Brookings Institution in Washington, says there is also "considerable concern that Iran and groups like the Lebanese Hezbollah might engage in terror attacks in the wake of an Israeli air strike". "Iran has at times used such attacks to strike out at enemies, particularly those it cannot hit by other means," he adds. There is already, he points out, a kind of clandestine war under way.

"Israel and Iran are already striking at each other (Israel with more success and doing so in a way that is more targeted)," Mr Byman explains, referring to the assassination of Iranian nuclear scientists. "I'm not sure Israel would increase attacks in the wake of a strike," he notes, "but Iran would."

Mr Byman is uncertain about how effective such Iranian operations might be.

"Iran's reported attempted attacks in India and Thailand show it remains determined to strike at Israel, presumably in retaliation for Israeli killings of Hezbollah figures like Imad Mughniyeh and the suspected attacks on Iranian nuclear scientists."

"However, these recent attacks were not well executed, suggesting that Iran's services' professionalism is uneven," he argues. Overall, experts believe that the Iranian government is going to have to calibrate its response to any attack carefully. Karim Sadjadpour, an Iran expert at the Carnegie Endowment for International Peace, told me: "If they respond too little, they could lose face, and if they respond too much, they could lose their heads."

"Iran will want to respond enough to inflame the regional security environment and negatively impact the global economy - in order to bring down international condemnation of the US or Israel - but stop short of doing anything that could invite massive reprisals from the United States."

"Frankly," Mr Sadjadpour says, "I'm not sure how they do that. If Iran tries to destabilise world energy supplies - whether launching missiles into Saudi Arabia's oil-rich eastern province or attempting to close the Strait of Hormuz - the US isn't going to stand aside idly." In the wake of any attack on its facilities, Iran might well, of course, go to the UN to seek some kind of diplomatic redress. This highlights a crucial set of legal questions relating to any military operation.

International law

For all the uncertainties as to whether Israel would attack Iran and indeed how Iran might respond, one thing is clear - in terms of international law, such a strike would be illegal.

The US-led invasion of Iraq resulted in a conflict that cost thousands of lives and cost billions of dollars

Professor Mary Ellen O'Connell, professor of international law at the University of Notre Dame, says for it to be considered legal, "the UN Security Council would need to authorise such a strike, because Iran has not launched an armed attack on either Israel or the United States".

"The UN Charter," she says, "makes clear that the use of force is generally prohibited unless a state is acting in self-defence to an armed attack occurring, or has Security Council authorisation." Israel, of course, would probably claim to be acting in some pre-emptive sense to forestall a future nuclear attack from Iran (though nobody yet believes Iran has a nuclear bomb). But Professor O'Connell says that an Israeli strike would still not be legitimate.

"There is a lively debate among international lawyers as to the point at which a state may respond to an armed attack: must it be under way or merely imminent?"

"There is virtually no support among experts for attacking to 'pre-empt' a hypothetical future attack." But surely countries do what they believe they have to do when vital interests are seen to be at stake?

For example, Nato attacked Serbia and Serbian forces in Kosovo, and the US and its allies invaded Iraq - both examples lacked UN Security Council approval. Professor O'Connell says that in both cases, the illegal use of force came with costly penalties.

"Compare those two conflicts," she notes, "to the lawful use of force to liberate Kuwait after Iraq's invasion. The United States came out of that conflict with a financial and moral gain."

Casualties

Many will also raise the question of the potential casualties that any Israeli strike might cause, especially since the operation would not be sanctioned by international law.

There is widespread support inside Iran for the country's controversial nuclear programme

Without knowing the targets to be hit, the timing of any strikes, and the likelihood of them being hit again, it is hard to determine potential casualty figures.

Experts say that the functioning nuclear reactor at Bushehr is unlikely to be a target due to the fact that it has nothing to do with a potential military programme and radiation leakage could cause widespread civilian casualties. But, of course, aircraft can be downed and bombs and other air-launched weapons can go astray.

There are, in addition, another set of Iranian reactions to any strike that matter.

How would Iranians themselves respond to any attack? What would be the impact upon Iran's nuclear programme? And what would be the implications for the Islamic regime in Iran itself? For now, it seems unclear that Iran has actually yet taken any decision to press ahead with a nuclear weapons programme.

Domestic factor

But Trita Parsi, author of the recently published, A Single Roll of the Dice - Obama's Diplomacy With Iran, says that if Israel attacks, Iran's position will change considerably. "I have not come across any observer who does not believe that the Iranian government's determination and desire for a nuclear deterrent would increase several-fold if Iran is attacked."

A military strike might rally Iranians around Ayatollah Ali Khamenei

The US assessment, he says, is that in the wake of an Israeli attack "the Iranians will push their program further underground, exit (or threaten to exit) the Non-Proliferation Treaty, kick out the International Atomic Energy Agency (IAEA) inspectors and dash for a bomb". "As some senior American military officials have said, bombing Iran is the fastest way to ensure an Iranian bomb," he adds.

Mr Parsi, who is president of the National Iranian American Council, also says that an Israeli attack would have political implications inside Iran too. "The Iranian regime is deeply unpopular and the wounds from their massive human rights abuses since the 2009 election are still open and bleeding." The regime, he adds, "has thus far failed to overcome this division with the people".

"However, an attack on Iran, particularly if the bombing campaign also results in high civilian casualties, will likely unite warring factions in Iran against the external aggressor." "This is what happened in 1980 with Saddam Hussein's invasion of Iran." "The attack helped consolidate Ayatollah Khomeini's grip on power, fuel nationalism and revolutionary zeal, and suspend the internal power struggles. The Iranian regime didn't survive in spite of Saddam's attack, but because of it."

That should be a sobering thought for Western and Israeli policy-makers, who from time to time flirt with the idea of regime change in Iran. It all suggests a stark conclusion - even a militarily successful attack from Israel's point of view will only delay Iran's nuclear programme for a few years. It might indeed confirm Iran in its desire to obtain a nuclear weapon. It might rally the Iranian population around the regime. And the regional consequences of any air strikes could be considerable; at worst precipitating conflict in the Gulf and on Israel's own borders.

No wonder, then, that the Obama administration seems to be trying to dissuade Israel from any attack - at least for now.

Many experts believe that there is still mileage in allowing sanctions to take their course but also - even now - in reaching out diplomatically to Tehran.

"Diplomacy has certainly not been exhausted," Trita Parsi told me. "The diplomatic efforts in the past few years have been few and short-lived," he notes.

"Political space for the type of sustained talks that are needed to generate a breakthrough has not existed in Washington or in Tehran. Rather than real negotiations, we have seen an exchange of ultimatums."

Karim Sadjadpour also thinks it may be worth another diplomatic push. But he feels the potential results will inevitably be limited.

"How do you reach a rapprochement with a regime that needs you as an adversary for its own ideological legitimacy?" he asks.

"Realistically," he concludes, "I think dialogue with Tehran can at best contain our differences with Iran, but it won't resolve them."

Iran's ballistic missile arsenal

Shahab-1 - Based on the Scud-B. Has a range of about 300km (185 miles) and uses liquid fuel, which involves a time-consuming launch

Shahab-2 - Based on the Scud-C. Has a range of about 500km (310 miles)

Shahab-3 - Based on the North Korean Nodong missile. Has a range of about 900km (560 miles) and a nominal payload of 1,000kg (2,205lb)

Ghadr-1 - Modified version of the Shahab-3, with a range of about 1,600km (1,000 miles). Carries a smaller, 750kg (1,654lb) warhead

Any Israeli attempt to destroy Iran's nuclear programme poses huge technical challenges for Israeli military planners. BBC Defence Correspondent Jonathan Marcus looks at some of the options open to Israel and asks whether it has the capacity to carry out such a mission.

Possible attack routes

Route 1: Northern route where Israeli jets would fly north and then east along the Turkish border with Syria and Iraq

Route 2: Central, more likely route, would take Israeli warplanes over Jordan and Iraq

Route 3: Southern route would take Israeli jets over Saudi air space. Possible route for return leg of their journey

Diane and Linda, There is far to much information on the page of the bbc website to thread, as it covers the complete page, I would therefore ask that youselves may visit the website to obtain the full information via the above link, thank you.

I sincerely hope that if Israel does attack Iran it happens after Jan.15 next year after Obama is hopefully defeated Netanyahu would be a fool to trust Obama given his Muslim upbringing. I truly believe Obama would side with the Iranians if it came to a war. It sickens me to say this but I think Obama will throw Netanyahu under the bus on this one.

Leaders of the Palestinian Islamist movement, Hamas, say they will not help Iran militarily in any conflict between Israel and the Islamic Republic. There is speculation in Israel that if it attacked Iran's nuclear facilities, it could face rocket fire from Hamas in Gaza and Hezbollah in Lebanon. Both are long-time allies of Iran.

But Mahmoud Zahhar, a senior leader of Hamas in Gaza, denied the group would get involved and told the BBC: "We are not part of any political axis." "If Israel attacks us we will respond. If they don't, we will not get involved in any other regional conflict," he added. Mr Zahhar questioned Hamas's ability to offer support from the Palestinian territory to the south of Israel, even if it wanted to. "Don't exaggerate our power. We are still suffering from the occupation, the siege and two wars in recent years," he said. Israel tightened its blockade of Gaza in 2007 after Hamas seized control of the territory from forces loyal to Palestinian Authority President Mahmoud Abbas and his Fatah movement.

Ideological differences

Another senior Hamas official in Gaza, who did not want to be named, also insisted that Hamas would stay out of any conflict between Israel and Iran.

"What could we realistically do anyway? If we were to attack Israel, the response would be much stronger," he said.

Hamas has long relied on Iran for funding. It is estimated that tens of millions of dollars are transferred to Gaza every year.However, the same Hamas official suggested they were not strongly aligned in their beliefs. "Iran has been very generous with its money, but ideologically we have little in common," he said.

Although both Hamas and Iran are hostile towards Israel, which regards the Palestinian group as a terrorist organisation, Hamas supporters are Sunni Muslims while Iran has Shia Muslim majority.

This makes it much closer to Hezbollah, a Shia Islamist movement which operates in southern Lebanon. "I don't like the Iranians and the way they try to use their influence in the Arab world," commented the Hamas official to whom I spoke.

Syria backlash

In recent months, the uprising in Syria has created tensions between Hamas and the Iranian leadership.

Hamas and its political leader, Khaled Meshaal, were based in Syria until recently

While Iran continues to back the Syrian President, Bashar al-Assad, last month for the first time, Hamas publicly criticised the government in Damascus.

Speaking in Cairo, Hamas's Prime Minister in Gaza, Ismail Haniya, also commended "the brave Syrian people that are moving toward democracy and reform". Hamas has pulled all its leadership out of Damascus, including the head of its political bureau, Khaled Meshaal. The movement is looking for a new base. Egypt, Jordan, Qatar and Turkey are all possibilities.

Six world powers have urged Iran to enter "serious dialogue" on its nuclear programme "without preconditions".

The US, UK, France, Germany, Russia and China called on Iran to co-operate fully with UN inspectors and allow them to visit the Parchin military site.

The countries have until now disagreed on their approach to Iran, with the West seeking a tougher line and Russia and China urging conciliation.

Iran says its nuclear programme is purely for peaceful purposes.

But it is widely thought to be seeking to develop nuclear weapons.

On Wednesday, diplomats raised concerns about the secret military development site at Parchin, amid speculation of possible clean-up activities there.

The six countries, known as the P5+1, are attending the talks at Vienna headquarters of the UN's nuclear watchdog the International Atomic Energy Agency (IAEA) to prepare for future talks with Iran.

An IAEA board meeting had been adjourned for one day on Wednesday to allow for further talks after the envoys failed to agree on what line to take towards Iran.

Earlier this week the six powers accepted an Iranian offer to return to talks for the first time in over a year. No date or venue has been set.

'Concrete results'

After Thursday's discussions, the powers released a joint statement saying: "We call on Iran to enter, without pre-conditions, into a sustained process of serious dialogue, which will produce concrete results."

Ayatollah Ali Khamenei said Mr Obama's comments on military action were "an exit from illusion"

The statement said negotiations would "address the international community's long-standing concerns and that there will be serious discussions on concrete confidence building measures".

American envoy to the IAEA, Robert Wood, said Iran must now respond to international demands.

"If it does not provide the agency with the necessary co-operation, and I mean concrete co-operation, then the board of governors at its next meeting in June will have to look at further steps," he said.

"Iran is now on notice, it's been put on notice that it needs to comply with its obligations and it needs to do so forthwith."

The group also expressed concern that two previous visits to Iran by IAEA inspectors had failed to resolve questions the agency had, and urged Iran to co-operate in particular over the Parchin site.

The IAEA has previously said it suspects the Parchin site may be being used for nuclear weapons related testing.

IAEA inspectors last visited Parchin in 2005 and in February this year they were turned away despite "intensive efforts" to visit.

Iran suggested on Monday that it would be prepared to grant UN weapon inspectors access to Parchin in the future but the IAEA head said on Thursday that it had had no formal contact from the country about allowing access to the site.

The complex, south of Tehran, is dedicated to the research, development and production of ammunition, rockets and explosives.

The US and Israeli leaders did not, however, discuss an Israeli request for advanced US military technology that could be used against Iran, the White House said.

The denial came after an Israeli official suggested the country had asked the US for advanced "bunker-buster" bombs and refuelling planes that could improve its ability to attack Iran's underground nuclear sites.

Wow: I think the scene is getting to be (as some of your Cousins over on this side of the pond would say) a very HOT POTATO. Earlier today or late yesterday there was a blurb on my computer which I wanted to copy, but as luck would have it, I was not only having problems with PD Care's site; as my name seemed to have gotten lost in the shuffle due to a Problem at Care 2; but the we had a Communications Failure with our telephone ccompany as well, so my ability to use AOL was interrupted several times over a couple of hours, and it was similar to having someone flipping the on / off switch on your electric power so I lost the post. But there was a journalist who was trying to quote some HOT SHOT who was supposed to know something about Iran that we didn't know and he was of the firm belief that Ahmadinejad (sp?) already had his nuke weapons built and ready to go?? I can't confirm this, but I have no reason to doubt it's authenticity - simply based on the fact that Mr. Dictator has worked so very hard to keep us and any other inspectors away from several areas where there could very well be completed nuclear weapons as well as possible silos / those being where the loaded missiles could be fired from to places such as Israel etc. It's certainly not a good thought that such may be the case, but I think it is REALISTIC.

However, the former director of the Mossad spy agency, Meir Dagan, was cautious about an attack on Iran.

He told CBS's 60 Minutes programme: "An attack on Iran before you explore all other approaches is not the right way to do it.

"It's our duty to help anyone who likes to present an open opposition against the regime in Iran."

On Thursday, six world powers - the US, UK, France, Germany, Russia and China - said in a statement: "We call on Iran to enter, without pre-conditions, into a sustained process of serious dialogue, which will produce concrete results."

They called on Iran to co-operate fully with UN inspectors and allow them to visit the Parchin military site.

The International Atomic Energy Agency (IAEA) has previously said it suspects the Parchin site may be being used for nuclear weapons-related testing.

Earlier this week, the six powers accepted an Iranian offer to return to talks for the first time in over a year. No date or venue has been set.